WO2026020589A1 - Powertrain and tractor - Google Patents

Abstract

The embodiments of the present application relate to the technical field of power transmission. Disclosed are a powertrain and a tractor. The powertrain can be applied to new energy architectures. The powertrain comprises a first electric motor, a second electric motor, and a gearbox, which comprises a first driveshaft, a second driveshaft, a rear axle driveshaft, a first power transmission structure, a second power transmission structure, a first driving gear, a first driven gear, at least one second driving gear and at least one second driven gear, wherein the rear axle driveshaft is configured to connect to a rear axle; one end of the first driveshaft is configured to connect to a power take-off, and the other end of the first driveshaft is connected to the first electric motor; the first driveshaft is connected to the first driving gear; the second driveshaft is connected to the second electric motor; the second driveshaft is connected to each second driving gear; the first driving gear meshes with the first driven gear; and each second driving gear meshes with one second driven gear.

Description

Power units and tractors

Cross-reference to related applications

This application claims the benefit of Chinese Patent Application No. 202410987458.4, filed on July 23, 2024, the contents of which are incorporated herein by reference.

Technical Field

This application relates to the field of power transmission technology, specifically to a power unit and a tractor.

Background Technology

With the continuous development of tractor manufacturing technology, various transmission systems, such as uninterruptible power transmission systems and continuously variable transmission systems, are applied to the gear shifting of tractors. Harvesters, crushers, and other tractors typically require multiple gears to adapt to the high resistance conditions in farmland.

However, in actual transportation, rotary tillage, and plowing operations, the required tractor speed and torque vary considerably. Even with frequent gear shifts and speed adjustments, the tractor's engine rarely operates within its optimal speed range. This inability to adapt the tractor's operating speed to real-world conditions prevents it from operating at high power, resulting in poor reliability. Furthermore, the increasing complexity of transmission systems makes gear shifts prone to shocks and jerks, as well as tire slippage, further contributing to the poor reliability in practical applications. Given the development trends of tractors and other equipment, new energy infrastructure has reached a significant scale, with pure electric, range-extended electric, hybrid, fuel cell electric, and hydrogen engine powertrains becoming widely used in tractors. Therefore, this optimized and improved technical solution is also adapted to the new energy infrastructure, achieving energy conservation and emission reduction while addressing the issue of poor tractor reliability in existing technologies under real-world conditions.

Summary of the Invention

The purpose of this application is to provide a power unit and a tractor, which solves the problem of poor reliability of tractors in actual working conditions in the prior art.

To achieve the above objectives, the first aspect of this application provides a power device, the power device comprising a first... An electric motor, a second electric motor, and a gearbox, wherein the gearbox includes a first drive shaft, a second drive shaft, a rear axle drive shaft, a first power transmission structure, a second power transmission structure, a first driving gear, a first driven gear, at least one second driving gear, and at least one second driven gear, wherein the number of second driving gears and second driven gears are the same;

The rear axle driveshaft is used to connect the rear axle. One end of the first driveshaft is used to connect the power output device, and the other end of the first driveshaft is connected to the first motor. The first driveshaft is connected to the first drive gear, and the second driveshaft is connected to the second motor. The second driveshaft is connected to each of the second drive gears. The first drive gear meshes with the first driven gear, and each of the second drive gears meshes with a second driven gear.

A first power transmission structure is used to connect with a first driven gear to transmit power from a first electric motor;

The second power transmission structure is used to connect with any one of the second driven gears to transmit power from the second electric motor.

In the embodiments of this application, the gear diameter of each second driving gear is different, and the gear diameter of each second driven gear is different;

Each second driving gear meshes with each second driven gear in order of decreasing gear diameter, in order of increasing gear diameter.

In the embodiments of this application, the second power transmission structure, used to connect with any one of the second driven gears to transmit power from the second electric motor, includes:

The second power transmission structure is used to connect with the second driven gear corresponding to the target speed range in order to transmit the power of the second motor, wherein the target speed range is determined based on the gear diameter of the second driving gear and the gear diameter of the second driven gear.

In embodiments of this application, the power unit further includes an electronic power supply device;

The power supply terminal of the electronic device is connected to the first motor and the second motor, with the first motor located on one side of the second motor.

In the embodiments of this application, the power unit further includes a diesel engine and a generator;

The diesel engine is connected to the charging terminal of the electronic device via a generator;

Diesel engines are used to power generators;

A generator is used to charge electronic devices.

In the embodiments of this application, the power unit further includes a rectifier, an inverter, and a power controller;

The generator is connected to the charging terminal of the power supply electronic device via a rectifier, and the power supply terminal of the power supply electronic device is connected via a reverse converter. The inverter connects the first motor and the second motor, and the power controller connects the rectifier and the inverter;

A rectifier is used to convert the alternating current (AC) output from a generator into direct current (DC) to charge electronic devices.

The power controller is used to generate control signals based on the current control parameters of the first motor and the second motor, and to send the control signals to the inverter.

An inverter is used to respond to control signals and convert the direct current output from the power supply terminal of the power supply device into alternating current corresponding to the current control parameters, so as to power the first motor and the second motor respectively.

In the embodiments of this application, the power unit further includes a four-wheel drive drive gear, a four-wheel drive driven gear, a four-wheel drive transmission shaft, and a four-wheel drive clutch.

One end of the four-wheel drive clutch is used to connect to the front axle, and the other end of the four-wheel drive clutch is connected to the four-wheel drive drive shaft.

The four-wheel drive drive shaft is connected to the four-wheel drive driven gear, the four-wheel drive driving gear meshes with the four-wheel drive driven gear, and the four-wheel drive driving gear is connected to the rear axle drive shaft.

In the embodiments of this application, the first power transmission structure is further configured to connect with the first passive gear when the second power transmission structure is connected to any one of the second passive gears.

In embodiments of this application, a first power transmission structure, used to connect with a first driven gear to transmit power from a first electric motor, includes:

The first power transmission structure is used to connect with the first driven gear when the speed difference between the first driving gear and the rear axle drive shaft is less than a preset difference, so as to transmit the power of the first motor.

The second power transmission structure, used to connect with any one of the second driven gears to transmit power from the second electric motor, includes:

The second power transmission structure is used to connect with any one of the second driven gears when the speed difference between the second driving gear and the rear axle drive shaft is less than a preset difference, so as to transmit the power of the second motor.

The second aspect of this application provides a tractor, which includes a front axle, a rear axle, a power take-off device, and the aforementioned power device;

The power unit connects the front axle, rear axle, and power take-off device.

This application provides a power unit, which includes a first electric motor, a second electric motor, and a gearbox. The gearbox includes a first drive shaft, a second drive shaft, a rear axle drive shaft, a first power transmission structure, a second power transmission structure, a first gear drive gear, a first gear driven gear, at least one second gear drive gear, and at least one second gear driven gear. The rear axle drive shaft is used to connect to the rear axle. One end of the first drive shaft is connected to the power take-off device, and the other end is connected to the first electric motor. The first drive shaft meshes with the first gear drive gear. The second drive shaft is connected to the second electric motor and meshes with each second gear drive gear. The first gear drive gear meshes with the first gear driven gear, and each second gear drive gear meshes with a second gear driven gear. The power of the first and second electric motors is coupled and output through gear transmission. By matching the torque of the first and second electric motors, the torque is smoother, avoiding shift shocks and jerks during load changes, thus improving the reliability of the tractor. At the same time, by adjusting the output of the electric motors to achieve precise continuously variable transmission, the high-efficiency range of the electric motors is effectively utilized, thereby improving the efficiency of the tractor and making the tractor more reliable.

Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section.

Attached Figure Description

The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings:

Figure 1 schematically illustrates a first structural diagram of a power unit according to an embodiment of this application;

Figure 2 schematically illustrates a partial structural diagram of a power unit according to an embodiment of this application;

Figure 3 schematically illustrates a second structural diagram of a power unit according to an embodiment of this application;

Figure 4 schematically illustrates the structure of a tractor according to an embodiment of this application.

Explanation of reference numerals in the attached figures

1000 - Tractor; 10 - Power unit, 20 - Power take-off unit, 30 - Rear axle, 40 - Front axle; 100 - First electric motor, 200 - Second electric motor, 300 - Gearbox, 400 - Power supply unit, 500 - Diesel engine, 600 - Generator, 700 - Rectifier, 800 - Inverter, 900 - Power controller, 301 - First driveshaft, 302 - Second driveshaft, 303 - Rear axle driveshaft, 304 - First motor Force transmission structure, 305-second power transmission structure, 306-first driving gear, 307-first driven gear, 308-second driving gear, 309-second driven gear, 310-four-wheel drive driving gear, 311-four-wheel drive driven gear, 312-four-wheel drive drive shaft, 313-four-wheel drive clutch, 3081-high speed driving gear, 3082-low speed driving gear, 3091-high speed driven gear, 3092-low speed driven gear.

Detailed Implementation

To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the embodiments of this application and are not intended to limit the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

It should be noted that if the embodiments of this application involve directional indications (such as one side and adjacent), the directional indications are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indications will also change accordingly.

Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

The transmission systems of medium and high horsepower tractors primarily utilize power shift technology. Some tractors employ CVT (Continuously Variable Transmission) technology; however, CVT powertrains are complex in structure, requiring highly sophisticated manufacturing and maintenance. Tractors operate under heavy loads, high energy consumption, and high emissions during tasks such as plowing and ditching. Pure electric drive with a single motor is currently limited by battery technology and cannot be sustained under prolonged heavy-duty conditions.

To adapt to heavy-duty working conditions, hybrid tractors have been widely used. For example, electric motors drive the front and rear axles, while a diesel engine powers the power take-off unit, achieving diesel-electric hybrid drive for the tractor. However, when the diesel engine drives the power take-off unit, it wastes a lot of energy, causing the tractor to fail to meet energy conservation and emission reduction requirements.

Without employing a CVT continuously variable transmission, the power system of a tractor designed for heavy-duty conditions includes not only the engine, motor, and transmission system, but also other complex components such as planetary gear sets. The complex structure of the power system leads to numerous components, resulting in unreasonable spatial arrangements such as parallel connections of the travel motor and PTO (Power Take-Off) motor. This fails to meet the minimum wheelbase requirements of the tractor and the installation requirements of the cab. Furthermore, with an unreasonable power system layout, the output power cannot continuously increase to overcome the increased workload, resulting in a lack of power. The overall layout of the power system cannot meet the positional requirements of the PTO shaft and travel drive shaft, easily causing resonance and uneven power transmission. Moreover, the limited travel power output mode makes it unsuitable for conditions with large load variations.

Please refer to Figure 1, which schematically shows a first structural diagram of a power unit according to an embodiment of this application.

The power unit 10 in Figure 1 includes a first electric motor 100, a second electric motor 200, and a gearbox 300. The gearbox 300 includes a first drive shaft 301, a second drive shaft 302, a rear axle drive shaft 303, a first power transmission structure 304, a second power transmission structure 305, a first driving gear 306, a first driven gear 307, at least one second driving gear 308, and at least one second driven gear 309. The number of second driving gears 308 and second driven gears 309 are the same.

The rear axle drive shaft 303 is used to connect the rear axle. One end of the first drive shaft 301 is used to connect the power output device, and the other end of the first drive shaft 301 is connected to the first motor 100. The first drive shaft 301 is connected to the first drive gear 306. The second drive shaft 302 is connected to the second motor 200. The second drive shaft 302 is connected to each second drive gear 308. The first drive gear 306 meshes with the first driven gear 307. Each second drive gear 308 meshes with a second driven gear 309.

The first power transmission structure 304 is used to connect with the first driven gear 307 to transmit power from the first electric motor 100;

The second power transmission structure 305 is used to connect with any one of the second driven gears 309 to transmit power from the second electric motor 200.

The conventional power unit 10 in this embodiment is applied to a tractor with a new energy architecture to drive the tractor's movement or to drive the tractor to perform operations. In this embodiment, the power unit 10 includes a gearbox 300 and a first electric motor 100 and a second electric motor 200 arranged coaxially. Compared to a single-drive electric motor, the coaxial dual-drive electric motor improves the tractor's efficiency.

The gearbox 300 includes a first drive shaft 301, a second drive shaft 302, and a rear axle drive shaft 303. Power is transmitted from the first electric motor 100 via the first drive shaft 301, and from the second electric motor 100 via the second drive shaft 302. The power source of the motor 200. In this embodiment, the first drive shaft 301 and the second drive shaft 302 are arranged coaxially. Compared with the parallel structure of two electric motors, the power unit 10 of this application is more compact, making the space layout of the tractor more reasonable.

The gearbox 300 also includes a first power transmission structure 304, a second power transmission structure 305, a first drive gear 306, a first driven gear 307, at least one second drive gear 308, and at least one second driven gear 309. For ease of understanding, only two second drive gears 308 and two second driven gears 309 are shown in the figure. The first drive shaft 301 is connected to the first drive gear 306 for transmission, thereby transmitting the power of the first electric motor 100 to the power output device 20 or the rear axle drive shaft 303 via the first drive shaft 301. Each second drive gear 308 is connected to a second driven gear 309 for transmission, thereby transmitting the power of the second electric motor 200 to the rear axle drive shaft 303 via the second drive shaft 302.

The power unit 10 provides multiple speed modes. Specifically, it can be driven by the first motor 100 alone, the second motor 200 alone, or both motors 100 and 200 simultaneously. When the first motor 100 is required to provide power, the first power transmission structure 304 is connected to the first driven gear 307 to transmit the power of the first motor 100. When the second motor 200 is required to provide power, the second power transmission structure 305 is connected to any one of the second driven gears 309 to transmit the power of the second motor 200. It should be understood that the types of the first power transmission structure 304 and the second power transmission structure 305 are determined according to actual needs and can be meshing sleeves, wet clutches, synchronizers, etc., and are not limited here. For ease of understanding, in the embodiments of this application, both the first power transmission structure 304 and the second power transmission structure 305 are meshing sleeves. The power of the first electric motor 100 and the second electric motor 200 is coupled and output through a parallel shaft gear transmission, resulting in smoother torque delivery and avoiding shift shocks and jerks during load changes, thus improving tractor reliability. Simultaneously, through torque matching of the first electric motor 100 and the second electric motor 200, and by adjusting the motor output, continuously variable transmission (CVT) is achieved, enabling precise CVT and effectively utilizing the high-efficiency range of the electric motors. This further improves tractor efficiency and enhances its reliability.

In the embodiments of this application, the gear diameter of each second driving gear 308 is different, and the gear diameter of each second driven gear 309 is different.

Each second driving gear 308 meshes with each second driven gear 309 in order of decreasing gear diameter.

When the second driving gear 308 and the second driven gear 309 cooperate for transmission, the gear diameter will affect the transmission. Power ratio. When the diameter of each second driving gear 308 is different, and the diameter of each second driven gear 309 is the same, the second power transmission structure 305 can select different transmission ratios by connecting to any one of the second driven gears 309. Similarly, when the diameter of each second driving gear 308 is the same, and the diameter of each second driven gear 309 is different, the second power transmission structure 305 can select different transmission ratios by connecting to any one of the second driven gears 309. In this embodiment, the diameters of both the second driving gear 308 and the second driven gear 309 are different.

Each second driving gear 308 meshes with each second driven gear 309 in ascending order of gear diameter, according to a descending order of gear diameter. As shown in the figure, one of the two second driving gears 308 is a high-speed driving gear 3081 with a large gear diameter, and the other is a low-speed driving gear 3082 with a small gear diameter. Similarly, one of the two second driven gears 309 is a high-speed driven gear 3091 with a small gear diameter, and the other is a low-speed driven gear 3092 with a large gear diameter. The meshing of each second driving gear 308 with a second driven gear 309 includes the high-speed driving gear 3081 with a large gear diameter meshing with the high-speed driven gear 3091 with a small gear diameter, and the low-speed driving gear 3082 with a small gear diameter meshing with the low-speed driven gear 3092 with a large gear diameter. It should be understood that the spatial arrangement of the multiple second driving gears 308 and the multiple second driven gears 309 are set according to actual needs. They can be arranged from largest to smallest, from smallest to largest, or in random order. No limitation is made here.

In the embodiments of this application, the second power transmission structure 305 is used to connect with any one of the second driven gears 309 to transmit power from the second electric motor 200, including:

The second power transmission structure 305 is used to connect with the second driven gear 309 corresponding to the target speed range to transmit power from the second motor 200. The target speed range is determined based on the gear diameter of the second driving gear 308 and the gear diameter of the second driven gear 309.

In this example, the tractor operates in two modes: Mode 1 and Mode 2. Mode 1 corresponds to the low-speed mode driven by the second electric motor 200, and Mode 2 corresponds to the high-speed mode driven by the second electric motor 200. For ease of understanding, in this embodiment, the first target speed range corresponding to Mode 1 is 0 to 18 km/h, and the second target speed range corresponding to Mode 2 is 0 to 39.9 km/h. The second power transmission structure 305 is connected to the second driven gear 309 corresponding to the target speed range to transmit power from the second electric motor 200.

Specifically, when mode one is selected, only the second power transmission structure 305 is connected to the low-speed drive gear 3082 corresponding to the first target speed range, and the first transmission mechanism is not connected to the first driven gear 307. Connection. The power of the second motor 200 is transmitted sequentially to the rear axle drive shaft 303 via the second drive shaft 302, the low-speed drive gear 3082, and the low-speed driven gear 3092, so that the rotation of the rear axle drive shaft 303 drives the rear axle 30. At the same time, by adjusting the output of the second motor 200, stepless speed change is achieved to correspond to the first target speed range.

When mode two is selected, only the second power transmission structure 305 is connected to the high-speed drive gear 3081 corresponding to the second target speed range, and the first transmission mechanism is not connected to the first driven gear 307. The power of the second motor 200 is transmitted sequentially to the rear axle drive shaft 303 through the second drive shaft 302, the high-speed drive gear 3081, and the high-speed driven gear 3091, so that the rear axle 30 is driven by the rotation of the rear axle drive shaft 303. At the same time, by adjusting the output of the second motor 200, stepless speed change corresponding to the second target speed range is achieved.

Please also refer to Figure 2, which schematically shows a partial structural diagram of the power unit according to an embodiment of this application.

In embodiments of this application, the power unit 10 further includes an electronic device 400;

The power supply terminal of the electronic device 400 is connected to the first motor 100 and the second motor 200, with the first motor 100 located on one side of the second motor 200.

It should be understood that the type of power supply device 400 is set according to actual needs and is not limited here. For ease of understanding, in the embodiment of this application, the power supply device 400 is a ternary lithium battery pack. The power supply terminal of the power supply device 400 is connected to the first motor 100 and the second motor 200. After the tractor starts, the power supply device 400 supplies power to the first motor 100 and the second motor 200 respectively, thereby driving the tractor to move or work. In addition, the first motor 100 and the second motor 200 can also be driven by a fuel-powered structure such as a diesel engine, so that the power unit 10 in this embodiment can be applied to tractors with diesel structures, which will not be elaborated here.

In this embodiment, the first motor 100 and the second motor 200 are arranged adjacent to each other. Compared with the separate dual motor structure, the coaxial dual drive motor can meet the spatial arrangement requirements of the tractor's power output device 20, rear axle 30 and front axle 40, avoiding poor reliability caused by resonance and uneven power transmission, and thus enabling the power unit 10 to adapt to working conditions with large load changes.

Please also refer to Figure 3, which schematically shows a second structural diagram of the power unit according to an embodiment of this application.

In the embodiments of this application, the power unit 10 further includes a diesel engine 500 and a generator 600;

The diesel engine 500 is connected to the charging terminal of the power supply device 400 via the generator 600;

Diesel engine 500 is used to power generator 600;

Generator 600 is used to charge electronic device 400.

The types of diesel engine 500 and generator 600 are set according to actual needs and are not limited here. Diesel engine 500 is connected to the charging terminal of power supply device 400 through generator 600. Power supply device 400 powers generator 600 to start generator, and also powers first motor 100 and/or second motor 200 to start first motor 100 and/or second motor 200. Starting diesel engine 500 drives generator 600 to supply energy to generator 600, which in turn charges and stores energy in power supply device 400. The tractor's drive mode adopts range-extending mode, that is, the diesel engine 500 and generator 600 charge power supply device 400. Diesel engine 500 does not need to operate under the load conditions of tractor operation, but instead works in the working range with optimal fuel consumption and emissions to charge power supply device 400, achieving energy saving and emission reduction.

In the embodiments of this application, the power unit 10 further includes a rectifier 700, an inverter 800, and a power controller 900;

The generator 600 is connected to the charging terminal of the power supply device 400 through the rectifier 700. The power supply terminal of the power supply device 400 is connected to the first motor 100 and the second motor 200 through the inverter 800. The power controller 900 is connected to the rectifier 700 and the inverter 800.

The rectifier 700 is used to convert the alternating current output from the generator 600 into direct current to charge the power supply device 400.

The power controller 900 is used to generate control signals based on the current control parameters of the first motor 100 and the second motor 200, and send the control signals to the inverter 800.

Inverter 800 is used to respond to control signals and convert the DC power output from the power supply terminal of the power supply device 400 into AC power corresponding to the current control parameters, so as to supply power to the first motor 100 and the second motor 200 respectively.

A rectifier 700 is provided between the generator 600 and the power supply device 400, and an inverter 800 is provided between the power supply device 400 and the first motor 100 and the second motor 200. The rectifier 700 is used to convert the alternating current output by the generator 600 into direct current to charge the power supply device 400.

The power controller 900 is a device used to manage, monitor, and optimize electrical energy. In this embodiment, the power controller 900 is used to form the tractor's battery management system. (BMS). The power controller 900 can supply high voltage to the high-voltage components in the tractor through the power distribution unit (PDU) of the high-voltage distribution box, and can also communicate with the VCU (Vehicle Control Unit) via the CAN (Controller Area Network) bus. The power controller 900 generates control signals based on the current control parameters of the first motor 100 and the second motor 200, and sends the control signals to the inverter 800. The current control parameters can be the amplitude and frequency of the alternating current, etc., which will not be elaborated here. In response to the control signals, the inverter 800 converts the DC power output from the power supply terminal of the power supply device 400 into AC power corresponding to the current control parameters, so as to power the first motor 100 and the second motor 200 respectively.

In the embodiments of this application, the power unit 10 further includes a four-wheel drive drive gear 310, a four-wheel drive driven gear 311, a four-wheel drive transmission shaft 312, and a four-wheel drive clutch 313.

One end of the four-wheel drive clutch 313 is used to connect to the front axle 40, and the other end of the four-wheel drive clutch 313 is connected to the four-wheel drive drive shaft 312.

The four-wheel drive drive shaft 312 is connected to the four-wheel drive driven gear 311, the four-wheel drive drive gear 310 is connected to the four-wheel drive driven gear 311, and the four-wheel drive drive gear 310 is connected to the rear axle drive shaft 303.

The type of four-wheel drive clutch 313 is determined according to actual needs and is not limited here. For ease of understanding, in the embodiment of this application, the four-wheel drive clutch 313 is a wet multi-plate pressure clutch. When the four-wheel drive clutch 313 is engaged, the power of the rear axle drive shaft 303 is transmitted sequentially to the four-wheel drive drive shaft 312 through the four-wheel drive drive gear 310 and the four-wheel drive driven gear 311, causing the four-wheel drive drive shaft 312 and the rear axle drive shaft 303 to rotate synchronously. According to the actual working conditions of the tractor, the tractor is driven in four-wheel drive mode, further improving the reliability of the tractor.

In the embodiments of this application, the first power transmission structure 304 is also used to connect with the first passive gear 307 when the second power transmission structure 305 is connected to any one of the second passive gears 309.

In this example, the tractor operates in Mode 3, which corresponds to a heavy-load mode where the first electric motor 100 and the second electric motor 200 are driven together. When the tractor performs heavy-load operations such as traction, the load can easily become too large, causing the power of a single electric motor to be insufficient for the actual working conditions. When the tractor selects Mode 3 for heavy-load operations, the second power transmission structure 305 is connected to a second driven gear 309, and the first power transmission structure 304 is connected to the first driven gear 307. The power of the first electric motor 100 and the second electric motor 200 is coupled and output to the rear axle drive shaft 303, ensuring the tractor's speed remains in the low-speed, constant torque range of the electric motors, avoiding shift shocks and jerks, and resulting in smooth torque transmission. It should be understood that this can be achieved through the first... The reverse drive of the tractor by the electric motor 100 and/or the second electric motor 200 is not described in detail here.

In the embodiments of this application, the first power transmission structure 304 is used to connect with the first driven gear 307 to transmit power from the first electric motor 100, including:

The first power transmission structure 304 is used to connect with the first driven gear 307 when the speed difference between the first driving gear 306 and the rear axle drive shaft 303 is less than a preset difference, so as to transmit the power of the first motor 100.

The second power transmission structure 305, used to connect with any one of the second driven gears 309 to transmit power from the second electric motor 200, includes:

The second power transmission structure 305 is used to connect with any one of the second driven gears 309 to transmit power from the second motor 200 when the speed difference between the second driving gear 308 and the rear axle drive shaft 303 is less than a preset difference.

When switching from mode one or mode two to mode three, the first motor 100 adjusts its output to adjust the speed of the first drive gear 306. When the speed difference between the first drive gear 306 and the rear axle drive shaft 303 is less than a preset difference, the first power transmission structure 304 is then connected to the first driven gear 307 to transmit the power of the first motor 100, while avoiding power interruption.

In this example, the tractor operates in mode four, which corresponds to the low-speed mode driven by the first electric motor 100. When mode four is selected, only the first transmission mechanism is connected to the first driven gear 307 to transmit power from the first electric motor 100 to the rear axle drive shaft 303. It should be understood that the power take-off device 20 typically has a built-in clutch; when the clutch is engaged, the power from the first electric motor 100 is directly transmitted to the power take-off device 20 via the first transmission.

When operating in mode four, the tractor only performs stepless speed regulation within a fixed speed range. When the tractor needs to travel at high speed, the second electric motor 200 adjusts its output to adjust the speed of the second drive gear 308. When the speed difference between the second drive gear 308 and the rear axle drive shaft 303 is less than a preset difference, the second power transmission structure 305 connects to the second driven gear 309 to transmit power from the second electric motor 200, while avoiding power interruption. It should be understood that when the second power transmission structure 305 is connected to the second driven gear 309, the first power transmission structure 304 can disengage from the first driven gear 307 to achieve uninterrupted power shifting. Compared to power transmission systems with complex structures such as electro-proportional valves, the power unit 10 of this application can achieve uninterrupted power shifting, improving the efficiency of the tractor. At the same time, the torque output of the electric motor improves the smoothness of shifting, avoids the jerking sensation during shifting, and further improves the tractor's performance. The reliability of the tractor.

This application provides a power unit 10 including a first electric motor 100, a second electric motor 200, and a gearbox 300. The gearbox 300 includes a first drive shaft 301, a second drive shaft 302, a rear axle drive shaft 303, a first power transmission structure 304, a second power transmission structure 305, a first driving gear 306, a first driven gear 307, at least one second driving gear 308, and at least one second driven gear 309. The rear axle drive shaft 303 is used to connect to the rear axle. One end of the first drive shaft 301 is used to connect to a power output device, and the other end of the first drive shaft 301 is connected to the first electric motor 100. The first drive shaft 301 is connected to the first driving gear 306. The second drive shaft 302 is connected to the second electric motor 200 and is connected to each second driving gear 308. The first driving gear 306 meshes with the first driven gear 307, and each second driving gear 308 meshes with a second driven gear 309. The power of the first electric motor 100 and the second electric motor 200 is coupled and output through gear transmission. Torque matching between the first electric motor 100 and the second electric motor 200 ensures smoother torque delivery, avoiding shift shocks and jerks during load changes, thus improving tractor reliability. Simultaneously, precise continuously variable transmission by adjusting the motor output effectively utilizes the high-efficiency range of the motors, further improving tractor efficiency and enhancing its reliability.

Please refer to Figure 4, which schematically illustrates the structure of a tractor according to an embodiment of this application.

This application embodiment also provides a tractor 1000, including a front axle 40, a rear axle 30, a power take-off device 20, and the aforementioned power device 10;

The power unit 10 connects the front axle 40, the rear axle 30, and the power take-off unit 20.

Both the front axle 40 and the rear axle 30 are power transmission systems of the tractor 1000. Generally, the front axle 40 refers to the drive axle or steering axle at the front of the tractor 1000, and the rear axle 30 refers to the drive axle or steering axle at the rear of the tractor 1000.

The tractor 1000 also includes an actuator and other structural components. These other components are determined by the type of tractor 1000 and may include a boom and hydraulic cylinders, etc., and are not limited here. The type of tractor 1000 is also determined based on actual needs and may include tractors, excavators, cranes, etc., and is not limited here. The power take-off unit 20 is used to drive the actuator of the tractor 1000 using the power provided by the power unit 10. The type of actuator is determined based on actual needs and may include hydraulic pumps, etc., and is not limited here.

The power unit 10 drives the tractor 1000 to move or operate. The first electric motor 100 and the second electric motor 200 in the power unit 10 achieve continuously variable transmission by adjusting their output. The tractor 1000 offers smoother torque, higher efficiency, and greater reliability.

It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims (10)

A power unit, characterized in that the power unit includes a first electric motor, a second electric motor, and a gearbox, the gearbox including a first drive shaft, a second drive shaft, a rear axle drive shaft, a first power transmission structure, a second power transmission structure, a first driving gear, a first driven gear, at least one second driving gear, and at least one second driven gear, wherein the number of second driving gears and second driven gears is the same; The rear axle driveshaft is used to connect the rear axle. One end of the first driveshaft is used to connect the power output device, and the other end of the first driveshaft is connected to the first motor. The first driveshaft is connected to the first drive gear, and the second driveshaft is connected to the second motor. The second driveshaft is connected to each of the second drive gears. The first drive gear meshes with the first driven gear, and each of the second drive gears meshes with a second driven gear. The first motor and the second motor are connected in series on the same axis, and both the first motor and the second motor are used to adjust the output for stepless speed change. The first power transmission structure is used to connect with the first driven gear to transmit the power of the first electric motor; The second power transmission structure is used to connect with any one of the second driven gears to transmit the power of the second electric motor. According to claim 1, the power device is characterized in that the gear diameter of each second driving gear is different, and the gear diameter of each second driven gear is different. Each of the second driving gears meshes with each of the second driven gears in order of decreasing gear diameter, in order of increasing gear diameter. According to claim 2, the power device is characterized in that the second power transmission structure is used to connect with any one of the second driven gears to transmit the power of the second electric motor, comprising: The second power transmission structure is used to connect with the second driven gear corresponding to the target speed range to transmit the power of the second motor, wherein the target speed range is determined based on the gear diameter of the second driving gear and the gear diameter of the second driven gear. The power unit according to claim 1, wherein the power unit further comprises an electronic power supply device; The power supply terminal of the electronic device is connected to the first motor and the second motor, with the first motor located on one side of the second motor. The power unit according to claim 4 is characterized in that the power unit further includes a diesel engine and a generator; The diesel engine is connected to the charging terminal of the power supply device via the generator; The diesel engine is used to supply power to the generator; The generator is used to charge the power supply device. The power unit according to claim 5 is characterized in that the power unit further includes a rectifier, an inverter, and a power controller; The generator is connected to the charging terminal of the power supply device through the rectifier, the power supply terminal of the power supply device is connected to the first motor and the second motor through the inverter, and the power controller is connected to the rectifier and the inverter; The rectifier is used to convert the alternating current output by the generator into direct current to charge the power supply device. The power controller is used to generate a control signal based on the current control parameters of the first motor and the second motor, and send the control signal to the inverter; The inverter is used to respond to the control signal and convert the DC power output from the power supply terminal of the power supply device into AC power corresponding to the current control parameters, so as to power the first motor and the second motor respectively. According to claim 1, the power unit is characterized in that it further includes a four-wheel drive drive gear, a four-wheel drive driven gear, a four-wheel drive transmission shaft, and a four-wheel drive clutch. One end of the four-wheel drive clutch is used to connect to the front axle, and the other end of the four-wheel drive clutch is connected to the four-wheel drive drive shaft. The four-wheel drive drive shaft is connected to the four-wheel drive driven gear, and the four-wheel drive driving gear is connected to the four-wheel drive... The passive gears mesh, and the four-wheel drive drive gear is connected to the rear axle drive shaft. According to claim 1, the power device is characterized in that the first power transmission structure is further configured to connect with the first passive gear when the second power transmission structure is connected to any one of the second passive gears. According to claim 1, the power device is characterized in that the first power transmission structure is used to connect with the first driven gear to transmit the power of the first electric motor, comprising: The first power transmission structure is used to connect with the first driven gear when the speed difference between the first driving gear and the rear axle drive shaft is less than a preset difference, so as to transmit the power of the first motor. The second power transmission structure, used to connect with any one of the second driven gears to transmit power from the second electric motor, includes: The second power transmission structure is used to connect with any one of the second driven gears when the speed difference between the second driving gear and the rear axle drive shaft is less than a preset difference, so as to transmit the power of the second motor. A tractor, characterized in that it comprises a front axle, a rear axle, a power take-off device, and a power unit according to any one of claims 1 to 9; The power unit is connected to the front axle, the rear axle, and the power output device.